In general, in a server room managing air conditioning control apparatus, there is performed air conditioning by temperature/humidity adjustment based on conditions where a mechanism similar to that oriented for a general building is provided, and airflow on the peripheries of information instruments is optimized, and so on, whereby achievement of energy saving enhancement is widely performed.
In recent years, an information amount has been increased by popularization of the Internet, and the like, whereby data centers, each of which is provided with such a server room, have been built more, and enhancement of energy saving performance of these facilities has been widely regarded as a subject.
In the case where loads to be subjected to air conditioning are information instruments as in such a data center, there are features different from those in air conditioning control oriented for the general building, such that most of the loads are sensible heat loads, that setting temperature/humidity just need to be within fixed ranges, and that ventilation for preventing an increase of a CO2 concentration is unnecessary since CO2 is not generated in the loads.
Accordingly, there is a technology for performing air conditioning in such a manner that, the data center is composed to be partitioned into two spaces, which are an air supply-side space (cold area) to servers and an air discharge-side space (hot area) therefrom, that returned air from an inside of the server room is taken in and subjected to temperature control, and that the air is circulated so as to be supplied again into such a room inside.
With such a configuration, a temperature gradient in an area of the room inside is reduced, and in addition, variations of an air supply temperature are reduced, whereby air conditioning control with a high energy-saving effect and good efficiency can be performed.